1 07/07/75  Static Handlers
 2 
 3 A new feature has been added to the system which improves the system's
 4 performance with respect to its handling of certain user-ring system
 5 conditions. The user-interface change externally visible is in the signalling
 6 of certain system events. In particular, "alrm" and "cput" are no longer
 7 signalled, but are rather handled directly by system code. Similarly, there is
 8 a change in the signalling of "no_write_permission" and "not_in_write_bracket"
 9 such that these, also are not signalled IF THE SEGMENT CAUSING THE CONDITION TO
10 BE RAISED HAS ITS COPY SWITCH ON (type "help copy_on_write").
11   Handlers for "cput" and "alrm" used to be established in the process overseer
12 of a process. This reuqired users wishing to write their own process overseer
13 to know that this was necessary. This strategy has changed such that the
14 "real_init_admin" program for a process takes on this task thereby relieving
15 writers of process overseer programs from knowing about this special process
16 (ring) initialization requirement.
17   Process overseers that establish timer_manager_ as the handler for "cput" and
18 "alrm" will continue to work although this effort is no longer necessary and
19 indeed ignored. If a process overseer establishes any other procedure as the
20 handler for these conditions, this no longer works in the same fashion.